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Subject: search.filters.subject.Rhamnolipid

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    Remediation of Waste Engine Oil Contaminated Soil using Rhamnolipid based Detergent Formulation
    (Elsevier, 2023) Jain, Amit; Gupta, Suresh; Chattopadhyay, Pradipta
    The utilization of waste substrates for rhamnolipid synthesis is a worthy alternative to conventional substrates to reduce the production cost of rhamnolipids. Rhamnolipid produced by Pseudomonas aeruginosa gi |KP 163922| using waste engine oil as substrate was investigated in batch and semi-batch studies for soil bioremediation. Green liquid detergent formulations were prepared by using environment-friendly builder (sodium citrate) and filler (isopropyl alcohol). Rhamnolipid, a biosurfactant was utilized in place of chemical surfactant to prepare the liquid detergent formulation. The formulations at different rhamnolipid concentrations i.e., below critical micelle concentration (CMC), at CMC, and above CMC, were tested for soil remediation efficiency. Each detergent formulation was characterized based on emulsification index (EI24%), surface tension reduction, foam ability, and foam stability. The in-house rhamnolipid based formulations above CMC, recovered oil up to 82.02 ± 0.938 % from contaminated soil with maximum surface tension reduction and foam volume as 26.5 ± 0.412 mN/m and 51.10 ± 1.37 mL respectively. The proposed remediation strategy demonstrated that the recovery of oil is possible at room temperature conditions. The performance properties including detergency and foaming of rhamnolipid based liquid detergent formulations were also compared with commercial rhamnolipid and other detergents.
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    Rhamnolipid production by Pseudomonas aeruginosa (SSL-4) on waste engine oil (WEO): Taguchi optimization, soil remediation, and phytotoxicity investigation
    (Taylor & Francis, 2023-09) Jha, Prabhat Nath; Gupta, Suresh; Jain, Amit
    Environmental concerns and rising biosurfactant demand emphasize the need for this study. The objective is to maximize rhamnolipid-biosurfactant production by Pseudomonas aeruginosa (SSL-4) utilizing waste engine oil (WEO) as the sole substrate for use in soil bioremediation and commercial production. Using an L16 Taguchi orthogonal array, a signal-to-noise ratio, and an analysis of variance (ANOVA), the effects of environmental (pH, incubation temperature) and dietary parameters (carbon source concentration, carbon/nitrogen (C/N) and carbon/phosphorus (C/P) ratio) are examined. Variations of the following parameters were made within a carefully selected range: incubation temperature of 25–40℃, pH range of 5–11, WEO concentration of 1–7% (v/v), and C/N and C/P ratios of 10–40. Response variables in this batch study include surface tension reduction (mN/m), dry cell biomass (DCBM) (g/L), and rhamnolipids yield based on substrate consumption, YP/S (g/g). Rhamnolipid was synthesized under optimal conditions, providing a yield of 21.42 g/g. The oil recovery of 74.05 ± 1.481% was achieved from oil-contaminated soil at a CMC of ∼70 mg/L. FTIR, 1H NMR, and UPLC-MS techniques were utilized for the characterization of rhamnolipids, and AAS for determining heavy metals concentration in WEO and residual waste engine oil (RWEO). The Germination Index (GI) of ∼82.55% indicated no phytotoxicity associated with synthesized rhamnolipid.
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    Characterization and oil recovery application of biosurfactant produced during bioremediation of waste engine oil by strain Pseudomonas aeruginosa gi|KP 16392| isolated from Sambhar salt lake
    (Taylor & Francis, 2021-05-05) Jain, Amit; Gupta, Suresh
    Halophilic bacterium, Pseudomonas aeruginosa gi|KP 16392| isolated from Sambhar salt lake in the southwest region of the city of Jaipur, India was tested for the first time for potential application in waste engine oil bioremediation and simultaneous biosurfactant production. In this study, the batch experiments were performed on culture grown in mineral salt medium supplemented with 5% (v/v) waste engine oil as the sole carbon source incubated for a week at pH 7.0, maintaining 35 °C and 150 rpm. The bacterial growth was monitored by the optical density and dry biomass content measurements. The biosurfactant production was affirmed with the reduction in surface tension of the culture medium from 72 ± 0.36 to 29.61 ± 0.14 mN/m. Of the total waste engine oil fed, 74.35 ± 0.037% was consumed and biodegraded to secondary metabolites. The biosurfactant yield was found to be approximately 1.02 g/L. The functional groups in the product, identified with the Fourier transform infrared spectroscopy confirms to be rhamnolipid and characterized using microbial adhesion to hydrocarbon (math) test and methyl assay. The emulsification activity of the produced biosurfactant was assessed for various hydrophobic substrates and was found to be comparable to the chemical surfactant (sodium dodecyl sulfate). The biosynthetic pathway (de novo synthesis) used by microbial strain to form rhamnolipid is schematically represented. The performance of the purified biosurfactant in oil recovery application was tested using a simulated waste engine oil contaminated soil and it showed excellent surface activity.